My jealousy

I know that when I'm not around, my bf checks out other girls and stares at naked girls online. But I can't understand that. I know it's normal, but I don't do it? Is it so wrong that I want to find someone like me? Who I know just has eyes for me and doesn't feed into all these girls exposing themselves? I'm all for you having your freedom to do what you want, but in my heart I hope my bf doesn't look because he has a good thing at home. I asked him if he looks when I'm not there, he said no. Then o asked him to be honest with me, and he said yes. It hurt to hear him admit it. But it is the truth, and what I expected of him was unrealistic. So, how do I make this jealousy go away? Or am I always going to be too loyal, and he just enjoy the view of all these women...